RU2599328C1 - Wideband small-size ferroelectric-ceramic antenna - Google Patents

Abstract

FIELD: antenna.

SUBSTANCE: invention relates to transceiver antennae for receiving and transmitting both digital and analogue signals. Antenna includes active element connected to grounding board made in form of parallelepiped of size L×W×H, where L is length, W is width, H is height, from ferroelectric ceramic material with high dielectric permittivity value ε≥1000 in working frequency range, and with anisotropic values of frequency dispersion of dielectric permittivity in body of active element: along its height: ε_H(ω) and at its base: ε_LW(ω) with ratio ε_H(ω)/ε_LW(ω) < 0.7, and also residual polarization σ≥2 mcCl/cm² at boundary of active ferroelectric ceramic element with air, and into body of active element exciter is built in form of current conducting rod, located perpendicular to base, wherein electrodynamic exciter length is equal to

. To exciter, current lead in form of micro-strip is connected, lying continuously on top, lateral, and bottom surfaces of active element and having electrodynamic length to exciter equal to

where l is total length of micro-strip on upper and lower surfaces of active element, wherein active element is arranged in plane of printed circuit board of transceiver (mobile telephone) in area, where current conducting elements of printed circuit board are absent, and at distance not less than (0.7-1) H between long side of active element and earthing conductor of printed circuit board.

EFFECT: technical result consists in producing working band of about 2 GHz in range 0,7 to 2,75 GHz, and broader functional capabilities.

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Description

The invention relates to transceiver antennas for receiving and transmitting digital and analog signals. It can be used as an internal antenna for mounting on a printed circuit board, primarily for smartphones and mobile phones, but can also be used in other types of radio equipment (televisions, radios, laptops, tablets, etc.).

In modern smartphones, tablets, it is necessary to provide signal reception in the frequency range from 690 MHz to 2.75 GHz (GSM, GPS, GPRS, WiFi, LTE, etc.). Moreover, taking into account the difference in standards in different countries, it is required:

- almost continuous spectrum of the received signal in the ranges of 0.69-2.2 GHz,

- the antenna efficiency should not be lower than 40%.

The problem is that with small sizes, modern antennas (made using microstrip technology or technology using LTCC ceramic materials), placed in limited volumes of compact mobile device housings, are high-resonance antennas to achieve acceptable performance, which leads to a narrowing of the working bandwidth (up to 10%), which means an increase in the number of antennas (up to 6 or more pieces) necessary to fully ensure all the functionalities inherent in mobile devices in the frequency range 0.69-2.75 GHz. A large number of antennas built into a mobile device leads to an increase in the required area and volume for their placement, which, in turn, leads to a complication of the design, increased losses in strip transmission lines, the occurrence of electromagnetic compatibility problems, etc.

Known dielectric ceramic antenna element (http: //www.cti-int.com \ products \ pagsm-ceramic-pcb-mount-gam-antenna) mounted on a printed circuit board, manufacturer CTI (Communication, Tacking, Innovation) , UK. The active element made of dielectric ceramic is made in the form of a parallelepiped of size L × W × H, where L is the length of the active element, W is the width of the active element, H is the height of the active element, on the lower surface of which a conductive electrode is applied, and on the upper surface are metal conductors connected through a microstrip deposited on the side surface with a current-conducting electrode, forming two resonant antennas tuned to the resonant frequencies of 900 MHz and 1800 MHz.

The disadvantage of this design of the antenna element is the narrow bandwidth of the resonant antennas, namely 30 MHz for an antenna with a resonant frequency of 900 MHz and 100 MHz for an antenna with a resonant frequency of 1800 MHz, as well as the need for matching circuits with a subsequent radio frequency path.

Known ultra-wideband ferroceramic interactive access antenna, which can be used for various types of wireless communication systems, receiving, transmitting and transmitting devices, such as television and radio devices, laptops, tablets, smartphones, etc. (RU 119173, IPC H01Q 3/00, published on 08/10/2012). The antenna contains a radiator in the form of a ferroceramic element connected to the grounding board, which is made in the form of an elongated parallelepiped made of a ferroelectric material with a high dielectric constant ε≥1000, located half its length above the grounding board, which is a structural board with the transmitter-receiver circuitry assembled on it devices, and on the ferroceramic element near the end located above the grounding board, there is an excitation point having I electrical contact with the metal pin connected to a strip conductor line connecting the receiver transceiver.

A disadvantage of the known antenna is its rather large overall dimensions, in addition, the antenna is located above and outside the printed circuit board of the mobile phone, which leads to an increase in the size and thickness of the mobile phone, thereby deteriorating its consumer properties.

The invention is known (JPH11345518, IPC Н01В 3/00, publ. 12/14/1999), in accordance with which the dielectric antenna contains a base in the form of a parallelepiped, a current-conducting electrode, a radiating electrode and an earth electrode, which are deposited on the base. To form the base, a special dielectric composition is used, consisting of SPS polystyrene and high-frequency ferroceramics with a low loss tangent. Ceramics make up 5% to 60% of the base volume. The antenna is resonant, the resonance frequency of the antenna is determined by the length of the radiating electrode.

The disadvantage of this design is the narrow working band of the resonant antennas.

The objective of the invention is to create a single antenna module ultra-high frequency with a wide working band, replacing several antennas used in mobile devices.

The technical result is the improvement of operational characteristics, the expansion of the functionality of the device for the organization of additional radio channels.

а к возбудителю проведен токоподвод в виде микрополоска, расположенного непрерывно на верхней, боковой и нижней поверхностях активного элемента и имеющего электродинамическую длину до возбудителя, равную

где l - суммарная длина микрополоска на верхней и нижней поверхностях активного элемента, причем активный элемент расположен в плоскости печатной платы приемопередающего устройства (мобильного телефона) в зоне, в которой отсутствуют токопроводящие элементы печатной платы, и на расстоянии не менее (0,7-1)Н между длинной стороной активного элемента и земляным проводником печатной платы.The specified technical result is achieved by a broadband small-sized antenna containing an active element connected to the grounding board, made in the form of a parallelepiped of size L × W × H, where L is the length, W is the width, H is the height, made of ferroceramic material with a high dielectric constant ε ≥1000 in the operating frequency range and having anisotropic values of the frequency dispersion of the dielectric constant in the body of the active element: ε _H (ω) in its height and ε _LW (ω) in the base with ε _H (ω) / ε _LW (ω ) <0.7, as well as residual polarization σ≥2 μC / cm ² at the interface of the active ferroceramic element with air, and a pathogen is built into the body of the active element in the form of a conductive rod located perpendicular to the base, and the electrodynamic length of the pathogen is

and a current supply in the form of a microstrip located continuously on the upper, lateral and lower surfaces of the active element and having an electrodynamic length to the pathogen equal to the pathogen was made to the pathogen

where l is the total length of the microstrip on the upper and lower surfaces of the active element, and the active element is located in the plane of the printed circuit board of the transceiver device (mobile phone) in an area in which there are no conductive elements of the printed circuit board, and at a distance of at least (0.7-1 ) N between the long side of the active element and the earth conductor of the printed circuit board.

The technical result is achieved due to the following.

The active (transceiving) element of the antenna combines the properties of a multiresonant domain structure with a high refractive index and a directed charge bipolar system. By increasing the density of the coupled energy, on the basis of which a stream of radiated energy is formed, and, consequently, the radiation intensity of the antenna, it is possible to weaken the frequency dependence of the active component of the antenna input resistance. With this approach, it is possible to achieve a reduction in size and improvement of parameters by 50% or more.

The invention is illustrated by drawings, where in FIG. 1 shows a general view of the active element, FIG. 2 is an example of a specific embodiment of the active element, in FIG. 3 shows the location of the antenna on the printed circuit board of a mobile phone; FIG. 4 is a photograph of a printed circuit board with an antenna located on it; FIG. 5 shows the dependence of the antenna return loss coefficient on frequency; FIG. 6 shows the dependence of the standing wave coefficient on frequency; FIG. 7 shows the dependence of the antenna gain on frequency.

The active element (Fig. 1) is made in the form of a parallelepiped of size L × W × H, where L is the length of the active element, W is its width, H is its height.

The active element, which is a transceiver element, is made of ferroceramic material with a high dielectric constant in the operating frequency range and is polarized in the direction perpendicular to the element base (L × W).

Concrete example

As a material for the active element, ferroceramics based on barium titanite, barium zirconate and barium stannate are used in the ratio of mass percent: 90: 5: 5 (or a ratio of 91.8: 4.3: 3.9 of their molar percent) with the following main electrophysical parameters:

Loss tangent tan δ (ω) = 0.036 ÷ 0.0081;

The dielectric constant ε _LW (ω) = 1500 ÷ 2200;

The dielectric constant ε _H (ω) = 1000 ÷ 2000.

The ceramics were polarized by applying high voltage to the electrodes deposited on the upper and lower surfaces of the active element, followed by removal of the electrodes. The residual polarization of ceramics σ was 2 μC / cm ² .

A hole was drilled in the body of the active element, into which a conductive rod (pathogen) was soldered with a low-temperature solder 2. The current supply to the pathogen is made in the form of a microstrip 3 located on the upper, side, and lower surfaces of the active element. The geometric dimensions of the microstrip and its location on the surfaces of the active element are detailed in FIG. 2.

The active element is located on a printed circuit board with dimensions of 50 × 100 mm in the upper right corner of the board (Fig. 3). The foil strip on the board 10 mm wide under the active antenna element is removed.

The radiophysical parameters of the antenna were measured using a Signal Analyzer Agilent EXA # 90-10A signal analyzer from Agilent, USA. In FIG. Figure 4 shows a photo of the antenna located on the layout of the printed circuit board of a mobile phone. The measurement results are shown in FIG. 5 and FIG. 6.

In FIG. Figure 5 shows the frequency dependence of the antenna return loss coefficient. Over the entire frequency range from 960 MHz to 3 GHz, the value of the return loss coefficient is less than -5 dB, which is an acceptable result even for resonant antennas, but at the most interesting frequencies noted in FIG. 5 arrows, can reach values of -25 dB.

In FIG. Figure 6 shows the dependence of the standing wave coefficient on frequency. A coefficient value of less than 2 is typical of good resonant antennas. For the proposed implementation of the invention, the standing wave coefficient is less than two in almost the entire frequency range from 1 GHz to 3 GHz.

The antenna gain (Fig. 7) is greater than 0 dbm in the frequency range from 960 MHz to 2.7 GHz and about 2 dbm in the frequency range from 1.1 GHz to 2.4 GHz.

Thus, the data obtained as a result of the experiment confirm the possibility of obtaining the technical result indicated in the invention, which consists in creating a single microwave antenna module with a working band of the order of 2 GHz in the range of 0.7-2.75 GHz, replacing several antennas currently used in mobile devices, and expanding the functionality of the antenna.

Claims (1)

A small-sized broadband antenna containing an active element connected to the grounding board, made in the form of a parallelepiped of size L × W × H, where L is the length, W is the width, N is the height, made of ferroceramic material with a high dielectric constant ε≥1000 in the working the frequency range and having anisotropic values of the frequency dispersion of the dielectric constant in the body of the active element: ε _H (ω) in its height and ε _LW (ω) in the base with the ratio ε _Н (ω) / ε _LW (ω) <0, 7, as well as residual polarization σ≥2 μC / cm ² n and at the interface between the active ferroceramic element and air, and in the body of the active element, a pathogen is built in the form of a conductive rod located perpendicular to the base, and the electrodynamic length of the pathogen is

and a current supply in the form of a microstrip located continuously on the upper, lateral and lower surfaces of the active element and having an electrodynamic length to the pathogen equal to the pathogen was made to the pathogen

where l is the total length of the microstrip on the upper and lower surfaces of the active element, and the active element is located in the plane of the printed circuit board of the transceiver device (mobile phone) in the area in which there are no conductive elements of the printed circuit board, and at a distance of not less than (0.7- 1) N between the long side of the active element and the earth conductor of the printed circuit board.

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